Apparatus for cementing wells



Aug. 4, 1953 Filed Feb. 9, 1949 C. C. BROWN ETAL APPARATUS FOR CEMENTING WELLS 5 sheets-sheet 1 Aug. 4, 1953 c.V c. BRowN ETAL APPARATUSA FOR CEMENTING WELLS 5 Sheets-Sheet 2 Filed Feb. `9, 1949 C/Cero C. Brown NVNTOR' ,WMZJAZ Hr w ATTORNEYS Allg 4, 1953 c. c. BROWN Erm. 2,647,582

APPARATUS FOR CEMENTING WELLS Filed Feb. 9, 1949 5 Sheets-Sheet 3 A rroR/vf YJ Aug. 4, 1953 c. BRQWN mL 2,6475582 APPARATUS FOR CEMENTING WELLS Filed Feb. 9, 1949 5 Sl'xeets-SheetI 4 Allg- 4, 1953 c. c. BROWN ETA. 2,647,582

APPARATUS FOR CEMENTING WELLS Filed Feb. 9, 1949 5 Sheets-Sheet 5 A TTORNEYJ Still another object is to provide an improved separation plug having means thereon which is normally retracted to permit said plug to be readily pumped downwardly through the well casing and which is adapted to move into a position locking the plug against upward movement in the casing in the event the pressure therebelow exceeds the pressure above the plug to thereby prevent upward displacement of Said plug within the casing.

Other objects will appear hereinafter.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

Figure 1 is a view, partly in section and partly in elevation of the upper portion of an improved apparatus, constructed in accordance with the invention, and illustrating the separation plug latched in position therein,

Figure 2 is a continuation of Figure 1, showing the lower portion of the device,

Figure 3 is a horizontal, cross-sectional view, taken on the line 3 3 of Figure l,

Figure 4 is a horizontal, cross-sectional view, taken on the line Il-d of Figure l,

Figure 5 is a transverse, vertical sectional View of the upper portion of the apparatus with the latching mechanism released,

Figure 6 is a continuation of Figure 5, illustrating the separation plug within the well casing behind the cement column, and

Figure 7 is a schematic view of a well bore and casing, showing the cement slurry being introduced with the separation plug latched in position out of the line of flow,

Figure 8 is a similar view with the plug inserted behind the cement column, and

Figure 9 is a similar view illustrating the locking means on the plug in a position locking said plug against upward displacement in the casing.

In the drawings, the numeral I 0 designates a well bore having a well pipe or casing I I extending therethrough. The well casing is arranged to be lowered within the bore I0 in any suitable manner and has an upwardly closing back-pressure valve I2 co-acting with fluid outlet openings I3 in the lower portion of the casing. During running in or lowering of the casing, the pressure within the bore exteriorly of the casing and acting against the lower end of the valve maintains the same in a position closing the opening I3 to prevent entry of fluid into the casing, The valve is automatically moved downwardly to uncover and open the outlets I3- whenever the pressure within the interior of the casing string exceeds the pressure within the well bore I 0. As is well known, the well bore is ordinarily filled with fluid or mud and the casing is lowered through said fluid; during the lowering the interior or bore of the casing is lled with fluid in any suitable manner whereby when the casing is landed in iinal position, as shown in Figure '7, the casing is lled with uid to a desired level.

After the casing string has been lowered into final position, it is desirable to carry out the usual cementing operation and ordinarily cement is pumped downwardly through the casing string and being under pressure functions to force the fluid within the casing string outwardly through or past the valve I2 Which ifi 4 opened by the pressure. Cement then passes outwardly into the well bore through the outlets I3 and rises to a predetermined height around the casing to permanently bond the lower portion of the casing within the well bore.

In order to assure the discharge of the entire cement column from the casing string and in order to employ a driving fluid for maintaining the pressure on such cement column, it is usual practice to rdispose a separation plug behind the cement column to separate the cement from the driving uid. The present invention is concerned with the disposition of this separation plug in proper position immediately behind or on top of the cement column, and is arranged so that said plug may be properly inserted within the well casing without the necessity of halting or interrupting the pumping operation by which the cement is being introduced and without opening the casing to atmosphere.

In carrying out the invention, the improved apparatus A, which is adapted to releasably retain a separation plug B, is mounted on the upper end of the casing string and has a radial inlet conductor I5 which communicates with the interior of the apparatus and the bore of the casing below the plug B, whereby the cement may be introduced through the conductor I5 and will flow downwardly into and through the well casing. In this manner, the plug B is normally disposed out of the line of iiow of the cement. When suicient cement has been introduced, the plug B is released so that it may fall downwardly on top of the cement column. This release of the plug into the well casing behind the cement is accomplished without opening the upper portion of the casing to atmosphere and without interrupting the pumping operation so that the pumps may continue to run to urge the driving fluid behind the plug and force the entire cement column downwardly.

The plug B travels downwardly through the well casing behind the cement as the operation continues and said plug functions lto separate the cement from the driving fluid, as is clearly illustrated in Figure 8. When the cement has been discharged through the outlets I3 and the plug B is disposed in the lower portion of the well casing, said plug is constructed so that its upward movement or displacement within the casing is impossible. In other words, the plug B is provided with means actuated by an excessive pressure therebelow which will rmly lock said plug against upward displacement in the well casing, In this manner the plug `will form a closure which will prevent the cement from being forced back upwardly through the well casing in the event that excessive pressure might develop within the well bore.

The apparatus A is clearly shown in Figures 1 and 2 and includes a cylindrical body 20 having a radial inlet opening 2I in its wall, and having a valve seat member 20a secured within the lower portion of its bore below the inlet. A coupling collar 22 is welded or otherwise secured within the inlet opening 2I and this collar is adapted to receive the end of the inlet pipe or conductor I5 through which the cement and pressure uid are introduced into the well casing. The lower end of the valve seat member 20a is threaded into a mounting sleeve 23 which is rotatably secured to a pipe section 24 by means of ball bearings 25. 'Ihe pipe section 24 has its lower end arranged to be coupled to the upper end of the casing string. The balls ing against the lower end of the operating stem 33 through the tubular mandrel 50 and functions to hold the assembly C in a raised position. During the cementing operation, it may be desirable to rotate the casing and the rotatable connection by means of the balls 25 permits such rotation of said casing while the housing 20 remains stationary.

When it is desired to introduce the plug B so that said plug will separate the cement column from the driving fluid which driving uid is ordinarily the usual drilling mud, it is only necessary to move the operating stem 36 downwardly against the pressure acting against the stem and this will permit the assembly C to move downwardly therewith to seat the lower end 49 of the sleeve 4l on the seat 53. It is noted that since pressures across the assembly C are substantially equalized, the only force required to allow downward movement of the assembly is the force necessary to overcome the pressure acting against the relatively small cross-sectional area of the operating stem 36. When the lower end 49 of the sleeve 4l engages the slot 48, a direct flow from the inlet I to the wall casing is shut 01T but the pressure present in the inlet may still pass upwardly around the sleeve 4l and through ports 45 to the area above the plus B. Continued lowering of the operating stem 36 will result in the stem moving downwardly with respect to the assembly C which is now held stationary due to the engagement of the lower end 49 of the sleeve 4I with the valve seat 48; such continued lowering of the stem will move the conical or tapered head 6l at the lower end of said stem downwardly with respect to the resilient latching elements so that the smaller portion of the head moves into a plane in alignment with the lugs 59. When this occurs the latching elements 6i) may retract or move inwardly to disengage the locking lugs 59 thereof from the locking recess 6| and the pressure from the line l5 which is present above the assembly C and above the separation plug B will immediately drive the plug downwardly from the lower end of the sleeve 4I and into the well casing on top of the cement column.

The plug is inserted immediately behind the cement and will follow the cement column closely with the driving uid theoretically being behind the plug; the driving fluid is preferably the usual mud but may be any other type of pressure fluid. However, because the `cement column tends to fall away from the driving fluid, a temporary suction or vacuum is created below the operating stem immediately following introduction of the plug B and before the pumps can build up sufcient pressure to catch up with the falling column. During this temporary suction period, the sleeve 4l remains seated but as soon as the pressure below the stem exceeds the atmospheric pressure to which the upper end of the stem is exposed, the stem is returned to an upper position which lifts the assembly C to again unseat the lower end thereof from the valve seat 43. The sleeve 4l is thus returned to its uppermost position so that a direct flow from the line l5 into the casing may again occur to continue pumping the driving fluid directly into the casing behind the plug to force the cement into position within the well bore. It is apparent that there is no interruption of the pumping operation in order to insert the plug and the plug is forced into the well casing by the line pressure to assure substantially instantaneous introduction of the plug upon release of the latching elements 60. Closing of direct flow from the inlet to the casing is effected during the introduction of the plug with such direct iiow being automatically reopened after the plug is released.

As the pumping continues, the separation plug B will follow the cement column, as illustrated in Figure 8, and the upper and lower packing elements 5I and 55 of said plug will engage the wall of the well casing with the upper element 55 functioning to form a seal during such lowering. Also the packing sleeve 54 which is associated with the gripping slips y53 of the separation plug engages the wall of the well casing and this frictional engagement forms a drag which is sufficient to maintain the gripping slips at the upper end of the conical slip expanding surface 52 on the mandrel of said plug to maintain said slips 53 retracted during lowering. After the cement has been ejected or discharged from the well casing the plug B will, of course, be in the lower end of the casing and a release of the pressure from above or an excessive `building up of pressure below the plug will result in tending to cause upward movement of the plug through the casing. It is at this time that the slips `53 function to lock the plug B against such upward displacement. If upward movement of the plug tends to occur the higher pressure acting beneath the lower packing element 5I will move the mandrel 59 upwardly while the slips will be retained more or less stationary by the frictional engagement of their packing sleeve 54 with the wall of the casing, whereby the slip expanding surface 52 coacts with the slips 53 to expand them into gripping position. Thus, the plug will be denitely locked against any upward displacement and will function to absolutely prevent the cement from being forced back upwardly through the well casing.

Any suitable means may be employed for lowering the operating stem 33 to allow downward movement of the sleeve valve assembly C and for releasing the separation plug B and a preferred arrangement is illustrated in the drawings. As shown in Figure l, the operating stem 36 extends upwardly through the packing gland 39 and has a nut 62 threaded thereon, with said nut being spaced from the upper end of the gland 39 when the stem is in its raised position. To prevent premature lowering of the stem in the event the casing pressure normally acting to hold the stem 36 should be dissipated for any reason, a U- shaped locking spacer or clevis 63 is adapted to engage over the stem 36, being located between the gland 39 and nut 62. The spacer may have a spring clip 64 (Figure 4) secured therein so that a frictional engagement with the stem may be had. An eye 65 is welded or otherwise secured to the exterior of the spacer 63 to facilitate insertion and removal of the spacer between the gland 39 and the nut 62.

Above the nut 62 the stem 36 has a sleeve 53 mounted thereon and this sleeve is connected through a pin 61 to an operating lever 68 at a point intermediate the ends of the lever. One end of the lever is pivoted by means of a pin 59 to the upper end of a link Til with the lower end of the link being pivoted on a pin 'H between pivot ears 'F2 which are formed integral with and which extend upwardly from the closure 30. The linkage arrangement allows a swinging movement of the lever to impart a straight line movement to the stem 36. Obviously, when the spacer or clevis 63 is in position between the gland 39 and the nut 62, the lever 68 cannot be actuated to amies-ea Towermeioperatingfsterm38%: however; wl'ienfthe spacer 63 is removed from between the -nutG'Z andy the lgland 39, a downwardE movement of the outer endl ofA the lever 68 willi result' a down-'- ward movement of the* stem 35i'.`

Inforder to faeilitatethe removal' of thespa'cer (i3-'f and asubsequent downwardi swingingv of' the cuter end ofthe lever 68"- al cable'T may have one end secured to the outerend ofIn theleve'r' after which `the cableV is threaded:` throughthe eyet5"A of? said spacer; With thiisrarrangement, a pull on the cable T31" in' the direction or the arrow in Figure l will-result inaremovalofthe spacer 63,l with continue'dlpull on tli'e'cable" accomplishing a swinging ofv the lever" 6U? andi a resultant downward movenzients of thev operating stem; Asexplainedi downward movement of the stem will first' allow ylowering the valve sleeve assembly B to shut offthe direct communication between-tlieinlet line ISand thewell''casing after which thelatching: elementsa 6'03 willi release the separation plug to allow the latter to be forced by the inlet pressure into the. wellcasing behind the cementl column.

From the foregoing, it will be seen thatI a continuous methodof wellcementi-ng may be carried out, The cement is pumpeddownwardly through the casing. as illustrated in Figure 7 with the separation plug mounted in position within the Valve sleeve assembly C`. At thistime pressures across the plug Bh as well as across the assembly C. are substantially eolualized,V with the casing pressure acting against the lower endr of the operating stem 35i to maintain the assembly in its raised position. When it is desired to introduce the separation plug it is only necessary to actuate the cable 13 whereby the spacer B3 is removed and the operating lever 68 is swung to lower the operating stem 36. The initial lowering movement of the stem 36 results in seating the lower end 49 of the sleeve 4I on the internal sleeve lll to shut ofi a direct ilow from the conductor l5 to the well casing. Continued lowering of the operating stem effects a release of the latching elements 60 to disengage their locking lugs 59 from the locking recess 58 of the plug. Because the line pressure at this time is above the plug such pressure will immediately move the plug downwardly from the sleeve 4| and into the well casing and the plug is thereby released and introduced without the necessity of stopping the pumps or without opening the system to atmosphere. The pressure in the line I5 actually assures that the plug B will be inserted into the well casing and after the introduction of the plug, the operating stem 36 is subsequently lifted to return the sleeve valve assembly C to its upper position, by the pressure within the well casing.

The plug B functions to separate the cement from the driving iluid which is pumped into the casing behind the plug and said plug moves downwardly within the well casing behind said cement. After the cement has been discharged any excessive pressure beneath the plug will immediately set the slips 53 of said plug so that upward displacement of the plug is prevented and the pressure on the cement is maintained during setting of said cement. Following setting of the cement, the plug is drilled out in the usual manner. The particular construction of the plug B is subject to some variation since various types of packing elements may be substituted for the particular pressure seal flared sleeves which have been illustrated. The plug is normally maintained out of the line of flow of the cement so 10 as notte interfere with-tlieintroduction thereof andislsupp'orted in a position-permitting its'substantially instantaneous introduction when the apparatus is actuated.

Tliev foregoing descriptionY of the invention is explanatory thereof' andv various changes in the size; slfia'p'e'an'd materials, as well asin the details of'tiheillustrated construction may be made, with;- in the scope of the appended claims, without departing from thespirit of the invention,

I-l'avir1gdescribed"V the invention, we claim:

lf. An'appar-atus-for inserting a separation plug behind cement? a well pipe including, a well pipe' litwirrg'4 an inlet in its-upper portion, whereby cement and other iluidmay be pumped under press-ure intor` said' pipe, a-` housing defining a chamber abevethe inlet and communicating with tliepipe, a separation plugv element disposed within= tli'e chamber and out ofthe direct-line of the new' of c'ementb'einglintroduced, a'tubular valve element in said'I housing disposed above said inlet, and annular valve; seat in said'well pipe below said inlet, rneansfor' releasing said valve element fr seatingonsaidvalve seat to shut off the direct flow frornithel inlet to the well pipe,` and' means forisel'ectivelyintroducing said plug element into the' pipe behind the: cement. and in. advance of afi following pressure uid without halting the pumping: operation;

apparatuslfor inserting a separation plug behindy Cement in a well pipe including, a Ywell pipe having. anv inletin its upper portion, whereby cement and vother iiuid may be pumped into said casing, a tubular body connected to the upper portion of said casing and in communication with the casing above said inlet, movable valve means mounted in the body and arranged to be actuated to shut oit a direct flow from the inlet to the well pipe, a separation plug separate from and releasably connected to said body, and means operable from exteriorly of the body for actuating the valve and for subsequently releasing the plug from said valve means whereby said plug is introduced into the well pipe while the direct flow from the inlet to the pipe is shut off.

3. An apparatus as set forth in claim 2, together with means exposed to the pressure within the well pipe for coacting with the valve means to return the valve means to its original position allowing a direct flow from the inlet to the pipe after the plug is inserted in the pipe.

4. An apparatus as set forth in claim 2 wherein said valve means includes openings for directing the pressure from the inlet against the separation plug when direct communication between the inlet and pipe is shut 01T to assure release of said plug and insertion thereof into the well pipe.

5. An apparatus for inserting a separation plug behind cement in a well pipe including, a well pipe having an inlet line in its upper portion whereby cement and other fluid may be pumped into said pipe, a separation plug normally disposed completely out .of the direct line of iiow from the inlet to the pipe, valve means for shutting off the direct flow from the inlet to the pipe and for directing pressure against the plug in a direction to urge the plug into the pipe, and a connecting means detachably connecting said plug to said valve means whereby upon a release of said plug from said valve means said plug is introduced into the well pipe behind the cement.

6. An apparatus as set forth in claim 5, wherein the connecting means for detachably connecting the plug to the valve means is operable from exteriorly of the well casing and also wherein the valve means is constantly urged by the pressure Within said pipe toward a position allowing direct flow from the inlet to the pipe.

7. An apparatus as set forth in claim 5, together with means operated by the pressure within the pipe for returning the Valve means to its initial position're-establishing direct iiow from the inlet to the well pipe after the plug has been introduced into the pipe.

8. An apparatus as set forth in claim 5, wherein said connecting means includes a common control member for controlling closing of the Valve means and the release of said plug from said Valve means, said control member being operable from ,exteriorly of the well pipe.

9. An apparatus for inserting a separation plug within a well casing including, a well casing having an inlet in its upper portion, a housing mounted on the upper end of the casing, an annular valve seat within the casing below the inlet, a sleeve Valve assembly mounted within the housing and movable into engagement with the seat, to shut of a direct flow from the inlet into the well casing, means for normally maintaining the valve assembly in a position within the body and disengaged from the seat, whereby cement may be pumped through the inlet into the casing, means for moving the valve to a seated position to shut off the direct now from the inlet to the casing after the cement has been introduced, a separation plug releasably latched within the valve assembly, and means for releasing said plug to allow it ,to-v enter the casing when the valve assembly is seated. n

10. An apparatus as set forth in "claim 9, together with a common actuator accessible from exteriorly of the housing and connected with the sleeve valve and the plug releasing means, whereby operation of said valve and said plug releasing means may be controlled from exteriorly of said housing.

11. An apparatus as set forth in claim 9, together with means operated by the pressure Within the casing for returning the sleeve valve to its normal unseated position after the plug has entered the casing, whereby direct flow from the inlet to the casing is reestablished subsequent to the introduction of the plug into the casing.

CICERO C. BROWN. yERNEST L. POTTS.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,503,693 McLean Aug. 5, 1924 1,662,311 Hamer Mar. 13, 1928 1,772,871 MacClatchie Aug. 12, 1930 1,791,874 Rodgers Feb. 10, 1931 v 1,875,266 Santiago Aug. 30, 1932 1,882,099 Trouth Oct. 11, 1932 2,104,270 Owsley Jan. 4, 1938 2,223,388 Scaramucci Dec. 3, 1940 2,228,630 Kail Jan. 14, 1941 2,277,510 Courter Mar. 24, 1942 

